Slight improvement in Delhi's air quality as wind helps in dispersion of pollutants

 Pollution levels reduced slightly in national capital on Friday with favourable wind speed helping in dispersion of pollutants, according to India Meteorological Department officials. city recorded an air quality index (AQI) of 251 at 10 am. 24-hour aver AQI was 315 on Thursday, worst since February 12 (AQI 320).An AQI between 0 and 50 is considered 'good', 51 and 100 'satisfactory', 101 and 200 'moderate', 201 and 300 'poor', 301 and 400 'very poor', and 401 and 500 'severe'.

A senior scientist at IMD said dip in pollution levels was likely because of an improvement in wind speed (up to 10 kilometres per hour).NASA's satellite imry showed a large cluster of farm fires near Amritsar, Patiala, Tarn Taran, and Firozpur in Punjab, and Ambala and Rajpura in Haryana.

Ministry of Earth Sciences' Air Quality Early Warning System for Delhi said wind direction was rthwesterly on Friday, which is favourable for transport of pollutants from farm fires.According to System of Air Quality and Wear Forecasting and Research, contribution of farm fires to Delhi's PM2.5 concentration was around 6 per cent on Thursday. It was only around one per cent on Wednesday and around 3 per cent on Tuesday, Monday and Sunday.

PM10 levels in Delhi-NCR reduced from 300 microgram per cubic meter (µg/m3) on Thursday evening to 250 µg/m3 at 10 am. PM10 levels below 100 µg/m3 are considered safe in India.PM10 is particulate matter with a diameter of 10 micrometers and is inhalable into lungs. se particles include dust, pollen and mold spores.

level of PM2.5 -- finer particles which can even enter bloodstream -- was 141 µg/m3, down from 151 µg/m3 on Thursday evening. PM2.5 levels up to 60 µg/m3 are considered safe.

With Delhi-NCR bracing for months of poor air quality, experts have warned that high levels of air pollution can aggravate COVID-19 situation.Severe air pollution in Delhi is a year-round problem, which can be attributed to unfavourable meteorological conditions, farm fires in neighbouring regions and local sources of pollution.

According to an analysis by Council on Energy, Environment and Water, a Delhi-based think tank, transportation contributes most -- 18 to 39 per cent -- to Delhi's air pollution.Ro dust is second largest source of air pollution in city (18 to 38 per cent), followed by industries (2 to 29 per cent), rmal power plants (3 to 11 per cent) and construction (8 per cent). 

(IM CREDITS:PTI)